Computer studies on dynamics of a large-scale magnetic loop by the spontaneous fast reconnection model

The temporal dynamics of a large-scale magnetic loop is numerically studied on the basis of the two-dimensional spontaneous fast reconnection model. When a plasmoid, caused by the fast reconnection, propagates and collides with a wall boundary, across which plasma cannot flow, a large-scale magnetic loop is formed. The resulting magnetic loop is constructed by the reconnected field lines; inside the loop, the plasma, initially residing in the current sheet, is confined. As the reconnected field lines are piled up, the magnetic loop grows and swells outwards, so that a strong fast shock suddenly builds up at the interface between the growing loop and the strong reconnection jet. The fast shock, located ahead of the loop top, moves outwards with the growing loop, changing its strength with several peak and bottom Mach numbers. Accordingly, a localized spot-like region, where the plasma pressure is extremely enhanced, definitely comes out immediately ahead of the loop top. Along the loop side boundary, slow shocks stand, so that the resulting large-scale magnetic loop provides a very powerful energy converter in the sense that it is enclosed by slow and fast shocks. copyright 1996 American Institute of Physics